Improved catalyst compositions for the use in carbon dioxide reforming of methane to generate syngas are described herein.
Conversion of carbon dioxide and methane, two of the leading greenhouse gases, into useful chemical materials has gained interest. In particular, methods of converting carbon dioxide and methane into syngas, also known as synthesis gas, have been studied in chemical factories and oil refineries where a relatively large amount of carbon dioxide is generated. Syngas, which is primarily composed of hydrogen and carbon monoxide, can be used as feedstock for the production of higher hydrocarbons, such as fuels, or to produce chemical reaction intermediates, such as methanol.
Syngas can be produced from methane via either steam reforming or dry reforming. Dry reforming of methane, which uses both carbon dioxide and methane as reactants in the presence of a catalyst, is of interest because it produces syngas with a hydrogen-to-carbon monoxide ratio close to 1.0, which is desirable as a feedstock for the production of higher hydrocarbons. Catalysts for converting methane and carbon dioxide into syngas are known in the art. For example, U.S. Patent Application No. 2012/0184430 and Sakar et al., Catalysis Today, Vol. 198:1 (2012), disclose a catalyst for the carbon dioxide reforming of methane. U.S. Pat. Nos. 5,744,419, 6,680,006 and 7,432,222 disclose catalyst compositions for the conversion of methane into syngas.
The dry reforming process can lead to extensive carbon formation on the catalyst during reaction, leading to catalyst deactivation and reduced efficiency. Moreover, the water gas shift reaction (WGS), which occurs simultaneously with the dry reforming reaction, can result in the syngas having a lower hydrogen-to-carbon monoxide ratio.
Thus, there remains a need in the art for a catalyst that efficiently catalyzes the carbon dioxide reforming of methane to form syngas with a hydrogen-to-carbon monoxide ratio close to 1.0 and is resistant to deactivation from carbon accumulation.